Physics

Germanium Definition Germanium is a brittle, crystalline, grayish-white metalloid element that is found in coal, in zinc ores, and in several minerals. Its atomic number…

Silicon Definition Silicon is a metalloid element that occurs in both gray crystalline and brown noncrystalline forms. It is the second most abundant element in…

About Brass Definition Brass is a yellowish alloy of copper and zinc, usually 67 percent copper and 33 percent zinc. It sometimes includes small amounts…

Tarnish Definition Tarnish is a substance which forms on the surface of some metals and which stains them or causes them to lose their brightness.…

Thorium Definition Thorium is a silvery-white, radioactive metallic element of the actinide series. The only naturally occurring isotope of thorium, Th 232, is also its…

Titanite Definition Titanite is a very rare calcium titanium silicate that is an important ore of titanium. It is also called Sphene. Its crystals are…

Datolite Definition Datolite is a colourless mineral consisting of a hydrated silicate of calcium and boron in monoclinic crystalline form, occurring in cavities in igneous…

Carbonatite Definition Carbonatite is a carbonate rock of apparent magmatic origin, generally associated with kimberlites and alkalic rocks. It has been variously explained as derived…

Hessonite Definition Hessonite is an orange-brown variety of grossularite garnet also called essonite, cinnamon stone. Its general formula: Ca3Al2Si3O12. It is also known as cinnamon…

Clinohumite Definition Clinohumite is a monoclinic-prismatic mineral containing fluorine, hydrogen, iron, magnesium, oxygen, and silicon. It is an uncommon member of the humite group, a…

Jerrygibbsite Definition Jerrygibbsite is a rare silicate mineral with chemical formula: (Mn,Zn)9(SiO4)4(OH)2. It is member of the leucophoenite family of the humite group. It is…

Chondrodite Definition Chondrodite is one of the rarest and most beautiful of gemstones and it is occasionally faceted for collectors. It is a nesosilicate mineral…